Pros: long battery life, highly durable, easy setup
Cons: built-in mic is poor for outdoor conversations, not recommended for gym use
I've spent years looking for quality wireless headphones and have been continually disappointed; infrared signals provided poor fidelity and were bulky and uncomfortable.
The Motorola S305 headset is my preferred iPhone accessory; it pairs with my device as soon as I power it on, it can hold a charge for a full day, and I'm able to switch back and forth seamlessly between listening to music and taking a call (when AT&T permits me to have a cell signal).
The audio quality on calls is excellent, though I don't recommend making a call if you're out in the open air -- the built-in condenser mic picks up wind noise too easily.
This headset can be worn for extended periods without discomfort and are very lightweight. They don't come with a carrying case, but they're durable enough to stow in a backpack or laptop case without protection. Although the S305 are great to use during active sports or at the gym, they tend to short out if perspiration gets inside the phones themselves. Two thumbs up, particularly in light of the price.